蜂毒肽对成熟树突细胞诱导T细胞分化的免疫调节的影响

通过蜂毒肽(Melittin,MT)干预脂多糖(Lipopolysaccharide,LPS)刺激树突细胞(Dendritic Cell,DC)与淋巴细胞共培养,以探究MT对Th1/Th2分化的影响。用MTS检测LPS、MT对DC与淋巴细胞共培养活性;流式细胞术检测MT对LPS刺激DC与淋巴细胞共培养中Th1、Th2比例;ELISA检测LPS刺激DC与淋巴细胞共培养中细胞上清液中IL-4、INF-γ浓度。结果显示MT、LPS在一定浓度下刺激DC与淋巴细胞共培养的活性;在成熟的DC诱导下,MT能上调Th1/Th2比例、Th1百分率(P0.05)及IFN-γ浓度(P0.01);对IL-4浓度、Th2百分率无影响(P0.05)。本研究说明MT通过上调Th1细胞比例,IFN-γ浓度,促进Th1/Th2细胞向Th1方向分化途径对T细胞起免疫调节作用。     

TGF-β与IL-6介导的骨髓基质干细胞对EAE的双向调节作用研究

目的:探讨在实验性自身免疫性脑脊髓炎(EAE)治疗中TGF-β与IL-6介导的骨髓基质干细胞(BMSCs)的双向调节作用与机制。方法:分离纯化BMSCs,并与EAE大鼠动物模型淋巴细胞共培养,应用抗TGF-β和IL-6单克隆抗体封闭TGF-β或IL-6通路,ELISA检测不同比例MSC与淋巴细胞共培养中对细胞因子的作用,流式细胞仪检测MSC对Th细胞亚群分化的影响,过继免疫临床评分检测BMSC治疗中的关键通路。结果:1:10比例BMSCs共培养组与对照组相比,IL-17分泌量下降(P0.05),Treg细胞显著增高(P0.05)而Th17细胞显著降低(P0.05),共培养后的淋巴细胞进行过继免疫回输后,1:10干细胞共培养组临床评分显著降低(P0.05),而1:100比例共培养组与上述结果相反,中和TGF-β和IL-6抗体可以调节此免疫作用。结论:BMSCs通过TGF-β和IL-6通路调节免疫系统调节性T细胞(Treg)和Th17的细胞平衡,此过程与BMSCs剂量密切相关,本研究可为干细胞更好的临床应用提供理论基础。     

双歧杆菌完整肽聚糖对小鼠骨髓来源树突状细胞分泌IL-12的影响

目的探讨相同剂量双歧杆菌完整肽聚糖（WPG）在不同时间对小鼠骨髓来源树突状细胞分泌IL-12的影响。方法将双歧杆菌WPG与小鼠骨髓来源树突状细胞共培养,分别在加入WPG后0、12、24、36、48和60h收集培养上清液,用ELISA法测定不同时间点上清液中IL-12的量。结果双歧杆菌WPG与树突状细胞共培养后,上清液中IL-12的量在24h内逐渐升高,至24h达高峰,24h后呈下降趋势;同0h组比较,12、24和36h组IL-12分泌量明显增加（P〈0.05）,而48、60h组同0h组比较差异无显著性（P〉0.05）。结论双歧杆菌WPG能够刺激小鼠骨髓来源的树突状细胞分泌IL-12;双歧杆菌WPG对树突状细胞的免疫刺激存在时间效应关系。     

Th17分化调节机制及其在器官移植中的研究进展

Th17细胞是新近发现的第三类CD4+ T辅助细胞亚群,其所分泌的IL-17、IL-22等细胞因子在中性粒细胞趋化、组织重塑与修复及介导抗体蛋白的产生等具有重要作用.但Th17分化调节受外界环境影响较大,如转录因子、细胞因子、Th1、Th2和调节T细胞(Tregs)等,这些均具有决定初始CD4+ T细胞向Th17细胞的分化方向和免疫反应方向的调控作用.目前Th17在器官移植物免疫耐受中的作用越来越受到重视,明确Th17分化调节的各种影响因素,将为器官移植免疫耐受研究提供新思路.     

小鼠沙眼衣原体肺感染过程中Treg细胞与Th17反应关系

[目的]对沙眼衣原体在BALB/c小鼠肺部感染过程中CD4+ CD25+Foxp3+调节性T细胞(regulatory T cells,Treg)与Th17反应关系进行初步探讨.[方法]取6-8周龄的BALB/c小鼠,鼻腔吸入25 μL含5×103 IFU的沙眼衣原体鼠肺炎菌株(Chlamydia muridarum,Cm),建立沙眼衣原体小鼠肺感染模型.监测感染后不同时期小鼠体重变化;检测肺组织衣原体包涵体形成单位( IFU)及肺组织病理改变;利用流式细胞术检测Cm感染后小鼠体内Treg细胞百分率;ELISA检测肺组织上清液IL-6、TGF-β、IL-17、IL-2细胞因子的的表达;qRT-PCR检测KC( keratinocyte derived chemokine) mRNA和MIP-2( macrophage inflammatory protein-2)mRNA的表达差异.[结果]用5xl03 IFU Cm经鼻腔吸人感染后小鼠发生沙眼衣原体肺炎,表现为体重下降、肺组织大量炎症细胞浸润并可检测到衣原体繁殖.Cm感染后第3天,小鼠体内Treg细胞占CD4 +T细胞的百分比明显降,随后开始恢复,第7天恢复原来水平,一直持续到衣原体清除.TGF-β、IL-2的表达与Treg细胞动态变化一致.与Th17相关细胞因子IL-6、IL-17和Th17相关趋化因子KC、MIP-2的表达于第3天开始升高,至第7天达到最高水平,随后逐渐减少.[结论]在衣原体感染BALB/c小鼠过程中,Treg可能通过提供TGF-β并在IL-6帮助下促进Th17应答产生.     

Th17细胞分化、调节及效应研究进展

Th17细胞作为一个不同于Th1、Th2的细胞亚群,已经被证实在自身免疫病、感染等疾病中发挥重要的作用.为了进一步认识Th17细胞的效应机制,近来对于Th17细胞的分化及调节进行了深入的研究,证实TGF-β与IL-6或者IL-21的协同作用是诱导Th17细胞分化的关键因素,而IL-23在促进IL-17分泌,增强Th17细胞效应功能方面发挥重要作用.与Th1、Th2、Treg细胞特异性的转录调节因子T-bet、GATA3、Foxp3相对应,现证实ROR-γt(retinoid-related orphanreceptors-γr)是促进Th17细胞分化、调节其功能的特异性转录调节因子.Th17细胞通过分泌IL-17A、IL-17F、IL-21、IL-22、IL-6、TNF-α等细胞因子发挥效应功能.其中IL-21作为Th17细胞的一个自分泌调节凶子,在诱导Th17分化、抑制Th1、Treg功能方面发挥关键作用.而另一方面,近来发现,重要的T细胞生长因子IL-2在维持、促进Th1、Th2、Treg及CD8 T细胞功能活性的同时,却发挥着抑制Th17细胞分化的作用.Th1、Treg、Th17细胞的分化之间存在微妙的调节关系,TGF-β的水平、作用的时间决定着上述三群T细胞的分化结局.Th17细胞与Th1细胞均是自身免疫病及感染性疾病的重要效应细胞,二者的作用是否有时间、空间、功能方面的特异性?TGF-β如何调节两群效应细胞的分化方向及功能?以及Th17细胞在体内免疫平衡中的作用,是否可以通过Th17细胞诱导免疫耐受等,是人们急于回答的非常有意义的课题.     

IL-21/IL-21R信号在TNBS诱导小鼠炎症性肠病病变形成中的作用研究

探讨IL-21/IL21R信号在炎症性肠病病变形成中对肠固有层辅助T细胞应答的调控机制。利用IL-21R基因敲除小鼠(IL-21R KO),建立TNBS诱导的炎症性肠病动物模型。监测小鼠体重及生存率;HE染色观察小鼠肠组织形态结构及炎症反应情况;分离和提取肠固有层淋巴细胞(lamina propria lymphocyte,LPL),应用流式细胞仪检测Th1、Th2、Th17、Treg细胞比例和绝对数;ELISA法检测LPL培养上清中的细胞因子(IFN-γ、IL-4、IL-17A、IL-10)的分泌。结果显示:与WT小鼠相比,IL-21R KO小鼠体重下降更快,生存率明显降低;HE染色显示IL-21R KO小鼠肠管上皮损伤严重、隐窝大面积消失、大量炎性细胞浸润,并侵犯到黏膜肌层;IL-21R KO小鼠肠固有层Th1细胞应答显著增强,相反Th2、Th17和Treg应答明显抑制。因此,IL-21/IL-21R信号通过调节小鼠肠固有层Th细胞应答,在TNBS诱导的肠炎病变形成中发挥重要的保护性作用。     

Th17细胞分化和功能的研究进展

近年研究发现了效应性辅助性T细胞的新亚群-Th17细胞,它主要分泌IL-17、IL-17F、IL-21和IL-22等细胞因子。Th17细胞及其效应分子被认为与自身免疫病和其他多种疾病相关。该文从Th17细胞的发现、人和小鼠Th17细胞的分化、Th17细胞的效应性因子及与健康和疾病的相关性几个方面对目前的研究进展进行了综述。     

乳杆菌对牛乳β-乳球蛋白致敏小鼠淋巴细胞分泌Th1/Th2型细胞因子和抗体的体外影响

为了分析乳杆菌对致敏小鼠脾淋巴细胞分泌Th1/Th2细胞因子及抗体的体外影响,用牛乳β-乳球蛋白腹腔注射BALB/c小鼠建立过敏症模型,造模成功后,分离致敏小鼠的脾淋巴细胞并与4种活/死乳杆菌(107 CFU/mL)体外共同孵育,ELISA法检测细胞上清液中细胞因子(IL-12、IFN-γ和IL-4)和抗体(总IgE、β-Lg特异性IgE和总IgG)含量。4种活/死乳杆菌均可体外调节致敏小鼠脾淋巴细胞分泌细胞因子和抗体的水平,特别是热致死的发酵乳杆菌和嗜酸乳杆菌可提高淋巴细胞IL-12和IFN-γ的分泌,抑制IL-4的分泌,使其IFN-γ/IL-4比值(代表Th1/Th2细胞平衡)高于活菌,与空白对照组比较差异显著(P<0.05)。同时,这两株热致死菌还可显著下调细胞上清液中总IgE、特异性IgE和总IgG抗体的浓度(P<0.05)。试验结果表明乳杆菌可提高牛乳β-乳球蛋白致敏小鼠脾淋巴细胞的IFN-γ/IL-4比值,进而纠正Th2占优势的Th1/Th2失衡,下调抗体分泌量,且具有菌株特异性。     

低聚果糖对AOM/DSS诱导的结肠炎相关结直肠癌小鼠辅助性T细胞的调控作用

目的 探讨益生元低聚果糖（FOS）对结肠炎相关结直肠癌（CAC）小鼠肠道辅助性T细胞的调节作用。方法 将6周龄SPF级雄性C57BL6小鼠（体重18～20 g）随机分为对照组、模型组和干预组,每组10只。通过偶氮甲烷、葡聚糖硫酸钠构建CAC小鼠模型,干预组每日使用2 mg/kg b.w. FOS灌胃,持续10周。造模期间监测各组小鼠体重变化,造模结束后测量结肠长度和肿瘤数目。采用微球免疫分析法检测血清Th1/Th2/Th17相关细胞因子水平,流式细胞术分析肠系膜淋巴结内Th1、Th2、Th17细胞亚群比例。结果 与模型组相比,干预组小鼠结肠长度显著增加（t=3.106,P=0.006 4）,肿瘤数目显著减少（U=15.000,P=0.011 1）,血清中IL-17A(t=3.504,P=0.008 8)、TNF-α(t=2.381,P=0.030 0)等促炎细胞因子水平降低,肠系膜淋巴结Th17细胞比例显著降低（t=6.031,P=0.002 7）,Th1/Th2显著升高（t=2.419,P=0.038 7）。结论 FOS可调控CAC模型小鼠结肠内辅助性T细胞的分化,抑制肿瘤的发生。     

Dendritic cells matured in the presence of the lycopodium alkaloid annotine direct T cell responses toward a Th2/Treg phenotype

Annotine is a lycopodane-type alkaloid isolated from the Icelandic club moss Lycopodium annotinum ssp. alpestre. Annotine does not inhibit acetylcholinesterase, as some other lycopodium alkaloids do, and other bioactivities have not been reported. The aim of this study was to determine the effects of annotine on maturation of dendritic cells (DCs) and their ability to activate allogeneic CD4⁺ T cells. Human monocyte-derived DCs were matured in the absence or presence of annotine at a concentration of 1, 10 or 100 μg/ml. The effect of the annotine on maturation of the DCs was determined by measuring concentration of cytokines in culture supernatant by ELISA and expression of surface molecules by flow cytometry. DCs matured in the absence or presence of annotine at 100 µg/ml were also co-cultured with allogeneic CD4⁺ T cells and concentration of cytokines in supernatants determined by ELISA and expression of surface molecules by flow cytometry. When cultured alone, DCs matured in the presence of annotine secreted less of the pro-inflammatory cytokines IL-6 and IL-23 and had a tendency toward less secretion of IL-12p40 than DCs matured in the absence of annotine. However, when DCs were matured in the presence of annotine and then co-cultured with allogeneic CD4⁺ T cells they secreted more IL-12p40 and had a tendency toward secreting more IL-6 than DCs matured in the absence of annotine and then co-cultured with T cells. Allogeneic CD4⁺ T cells co-cultured with DCs matured in the presence of annotine secreted more IL-13 than T cells co-cultured with DCs matured in the absence of annotine, but stimulating the DCs in the presence of annotine did not affect T cell secretion of IFN-γ and IL-17. There was also more IL-10 in co-cultures of T cells and DCs matured in the presence of annotine than in co-cultures of T cells and DCs matured in the absence of annotine. These results show that annotine increases the ability of DCs to direct the differentiation of allogeneic CD4⁺ T cells toward a Th2/Treg phenotype, which may be of interest in the development of new treatments for Th1- and/or Th17-mediated inflammatory diseases.     

Decreased interleukin 27 expression is associated with active uveitis in Beh?et’s disease

Instruction

Interleukin 27 (IL-27) is an important regulator of the proinflammatory T-cell response. In this study, we investigated its role in the pathogenesis of Behçet’s disease (BD).

Methods

IL-27 mRNA in peripheral blood mononuclear cells (PBMCs) was examined by performing RT-PCRs. Cytokine levels in sera or supernatants of PBMCs, naïve CD4⁺ T cells, dendritic cells (DCs) and DC/T cells were determined by enzyme-linked immunosorbent assay. We used RNA interference in naïve CD4⁺ T cells to study the role of interferon regulatory factor 8 (IRF8) in the inhibitory effect of IL-27 on Th17 cell differentiation. Flow cytometry was used to evaluate the frequency of IL-17- and interferon γ–producing T cells.

Results

The expression of IL-27p28 mRNA by PBMCs and IL-27 in the sera and supernatants of cultured PBMCs were markedly decreased in patients with active BD. A higher frequency of IL-17-producing CD4⁺ T (Th17) cells and increased IL-17 production under Th17 polarizing conditions were observed in patients with active BD. IL-27 significantly inhibited Th17 cell differentiation. Downregulation of IRF8 by RNA interference abrogated the suppressive effect of IL-27 on Th17 differentiation. IL-27 inhibited the production of IL-1β, IL-6 and IL-23, but promoted IL-10 production, by DCs. IL-27-treated DCs inhibited both the Th1 and Th17 cell responses.

Conclusions

The results of the present study suggest that a decreased IL-27 expression is associated with disease activity in BD patients. Low IL-27 expression may result in a higher Th1 and Th17 cell response and thereby promote the autoinflammatory reaction observed in BD. Manipulation of IL-27 may offer a new treatment modality for this disease.     

Transforming growth factor-β protein inversely regulates in vivo differentiation of interleukin-17 (IL-17)-producing CD4+ and CD8+ T cells

TGF-β is a pleiotropic cytokine that predominantly exerts inhibitory functions in the immune system. Unexpectedly, the in vitro differentiation of both Th17 and Tc17 cells requires TGF-β. However, animals that are impaired in TGF-β signaling (TGF-βRIIDN mice) display multiorgan autoimmune disorders. Here we show that CD4(+) T cells from TGF-βRIIDN mice are resistant to Th17 cell differentiation and, paradoxically, that CD8(+) T cells from these animals spontaneously acquire an IL-17-producing phenotype. Neutralization of IL-17 or depletion of CD8(+) T cells dramatically inhibited inflammation in TGF-βRIIDN mice. Therefore, the absence of TGF-β triggers spontaneous differentiation of IL-17-producing CD8(+) T cells, suggesting that the in vivo and in vitro conditions that promote the differentiation of IL-17-producing CD8(+) T cells are distinct.     

Activity of CD4+ T-cell clones of type 1 and type 2 in generation of influenza virus-specific cytotoxic responses in vitro

The activity of distinct CD4+ T-helper cell (Th) clones in promoting secondary A/PR/8/34/Mt.S.(H1N1) (A/PR8) influenza virus-specific, class I-restricted cytotoxic T-lymphocyte (CTL) responses in vitro was examined. CD8+ T cells which had been purified by fluorescence-activated cell sorter from spleen cells of A/PR8-primed mice were used as responders. On their own, purified CD8+ T cells were unable to generate cytotoxic activity upon in vitro culture with A/PR8-infected stimulator cells. Significant cytotoxic activity was generated in cultures that were additionally supplemented with A/PR8-specific Th clones or cell-free supernatant from these clones. Although there were large differences among individual Th clones in this function, Th clones of type 1 (Th1) promoted, on average, significantly stronger cytotoxic responses than Th clones of type 2 (Th2). The differences in promotion of a cytotoxic response correlated with the amount of interleukin-2 (IL-2) or IL-4 secreted by individual Th clones. These two lymphokines accounted for the CTL-promoting activity of the respective Th clones, since addition of recombinant IL-2 (IL-2) or rIL-4 to Th-free cultures substituted fully for the respective Th clones. As observed with Th clones, rIL-2 was significantly more effective than rIL-4 in promoting a cytotoxic response. When used in combination, Th2 clones had an antagonistic effect on the generation of a CTL response by Th1 clones. This effect could be partially transferred with cell-free supernatant from activated Th2 clones and could be reversed by addition of excess rIL-2. Both consumption of IL-2 by Th2 and secretion of an inhibitory factor(s) appear to be involved in this phenomenon.     

双歧杆菌对过敏性哮喘儿童树突状细胞分泌IL-10、IL-12等细胞因子的影响

目的探讨双歧杆菌对过敏性哮喘儿童外周血单核细胞（PBMC）来源的树突状细胞（DC）分泌IL-1β、IL-6、IL-10、IL-12、IL-23和IFN-γ的影响。方法从15例过敏性哮喘儿童和15例非哮喘儿童的外周血单个核细胞诱导生成未成熟DC,加入双歧杆菌后继续培养DC2d,用ELISA方法检测培养上清中IL-1β、IL-6、IL-10、IL-12、IL-23和IFN-γ的水平。结果双歧杆菌能明显刺激哮喘儿童DC分泌IL-12、IFN-γ,IL-1β及IL-6和非哮喘儿童DC分泌IL-12、IL-10、IL-1β及IL-23水平增高。结论双歧杆菌能够刺激过敏性哮喘儿童DC分泌IL-12和IFN-γ,可能改变Th2优势分化,纠正Th1／Th2失衡。同时双歧杆菌还能刺激哮喘儿童DC分泌IL-1p及IL-6增高,达到促进,Th17细胞分化的作用。     

Role for IL-4 nonproducing NKT cells in CC-chemokine ligand 2-induced Th2 cell generation

NKT cells from C57Bl/6 mice are known to be the initial cellular source of IL-4 that acts as a trigger for Th2 cell differentiation. CC-chemokine ligand 2 (CCL2) has been described as an initial stimulator of IL-4 production by these cells; however, IL-4 was not produced by NKT cells from BALB/c mice even when Th2 cell responses were established in these mice. In this study, we found a new pathway for CCL2-associated Th2 cell generation in BALB/c mice. Splenic T cells from BALB/c mice produced IL-4 in response to CCL2 stimulation. However, IL-4 production was not seen in cultures of splenic T cells from CD1-/- mice (BALB/c origin), whereas, in the presence of CCL2, splenic T cells from CD1-/- mice produced IL-4 when NKT cells from wild-type mice were added. CCL2 induced IL-4 in cultures of NKT cells cocultured with naive T cells, but IL-4 was not produced by these cells cultured separately with CCL2. Interestingly, IL-4 was produced by naive T cells cocultured with NKT cells that were previously treated with CCL2 (CCL2-NKT cells). In addition, IL-4 was produced by naive T cells supplemented with a culture supernatant of CCL2-NKT cells. These results indicate that, through the production of a soluble factor(s) other than IL-4, NKT cells play a role in the CCL2-associated generation of Th2 cells.     

The E3 ubiquitin ligase adaptor Ndfip1 regulates Th17 differentiation by limiting the production of proinflammatory cytokines

Ndfip1 is an adaptor for the E3 ubiquitin ligase Itch. Both Ndfip1- and Itch-deficient T cells are biased toward Th2 cytokine production. In this study, we demonstrate that lungs from Ndfip1(-/-) mice showed increased numbers of neutrophils and Th17 cells. This was not because Ndfip1(-/-) T cells are biased toward Th17 differentiation. In fact, fewer Ndfip1(-/-) T cells differentiated into Th17 cells in vitro due to high IL-4 production. Rather, Th17 differentiation was increased in Ndfip1(-/-) mice due to increased numbers of IL-6-producing eosinophils. IL-6 levels in mice that lacked both Ndfip1 and IL-4 were similar to wild-type controls, and these mice had fewer Th17 cells in their lungs. These results indicate that Th2 inflammation, such as that observed in Ndfip1(-/-) mice, can increase Th17 differentiation by recruiting IL-6-producing eosinophils into secondary lymphoid organs and tissues. This may explain why Th17 cells develop within an ongoing Th2 inflammatory response.